Constant feed-rate material-handling device



Dec. 1, 1964 Y A. PIRRELLO 3,159,269

CONSTANT FEED-RATE MATERIAL-HANDLING DEVICE Filed Oct. 15, 1962 2 Sheets-Sheet 1 INVENTOR.

ATTORNEY Dec. 1, 1964 A. PIRRELLO 3,159,259

CONSTANT FEED-RATE MATERIAL-HANDLING DEVICE Filed Oct. 15, 1962 2 Sheets-Sheet 2 ill W 2?! It a 1 w w WW INVENTOR.

Y .Kzzfozzz'o ird/b United States Patent Antonio Pirrello, Lincoln Park, Mich, assignor to General Motors Qor'poration, Detroit, Minis, a corporation of Delaware Filed Get. 15, M62, era No. QIiiLdM '7 (llairns. (til. 1982;Z)

This invention concerns a vibratory material-handling device having a driving arrangement that provides a substantially constant feed-rate irrespective of the load in the material-retaining receptacle.

Vibratory material-handling devices, of the sort this invention is directed to, typically comprise a materialretaining receptacle supported on a base by a plurality of spring members. The material-retaining receptacle can take the form of a bowl with a track formed or attached to the inner wall thereof and spiraling upwardly from the bottom to the top of the bowl where an exit opening is formed. In this sort of receptacle, parts located as a common mass at the bottom of the bowl are driven upwardly along the track to the exit station for further disposition. Other forms of material-retaining receptacles may have the configuration of an elongated trough or tube, however in all instances, these ma terial handling devices are characterized by employing an electromagnetic or air-driven vibrator which serves to vibrate the receptacle at a predetermined frequency for dispensing the contents therefrom.

The feed-rate of devices of the above-described type is dependent upon several variables, among which the load in the bowl has been found to be a very important factor. Hence, when the bowl is loaded to capacity and the vibrator is adjusted for a predetermined part or material feed-rate, it has been found that the latter will progressively increase as the load in the bowl decreases. For this reason, it has been the practice to either maintain a substantially constant load in the bowl or make frequent adjustments in the operating frequency of the vibrator in order to maintain the same feed-rate during the dispensing operation.

The present invention alleviates the above-mentioned problem with material-handling devices of the sort described by providing a vibratory driving arrangement that permits the material-retaining receptacle to dispense the contents therefrom at a substantially constant rate without necessitating any adjustment of the load in the receptacle or the frequency of the vibrator. Stated broadly, this is accomplished in accordance with the invention by coupling a force-transmitting member between the material-retaining receptacle and the vibrator in a manner that permits the force impulses generated by the latter to be multiplied in magnitude at the point of force application. Moreover, a preloaded spring arrangement is associated with the force-transmitting member and the material-retaining receptacle so as to control movement of each and allow for efiicient energy transfer between the vibrator and the receptacle.

A more complete understanding of the present invention can be derived from the following detailed description when taken in conjunction with the drawings in which:

FIGURE 1 is an elevation view of two material-handling devices, each of which employs a force-transmitting apparatus made in accordance with the invention and driven by a common vibrator,

FIGURE 2 is a view taken on lines 2-2 of FIGURE 1,

FIGURE 3 is a view taken on lines 3--3 of FIGURE 1, and

FIGURE 4 is an illustration of the movement of the Eddfd Fatented Dec. 1, i954 Llzl force-transmitting apparatus during operation of the vibrator.

At the outset, it should be mentioned that although the present invention is shown employed with a feeder bowl of a type supported by a plurality of inclined springs on a support base, it should be understood that this arrangement is for illustrative purposes only, and that the invention can be used with other material-handling devices such as conveyor troughs, screens or other forms of vibratory conveyors, feeders or screens in the material-handling Referring now to FIGS. 1-3, a pair of material-handling devices typically referred to as feeder bowls are shown driven by a single air-operated vibrator which is connected through force-transmitting means, made in accordance with this invention, to the underside of each of the bowls. Each of the material-handling devices lit and 12 incorporates identical components and for this reason hereinaften reference will be made to the parts of one device only, it being understood that identical and corresponding parts are incorporated with the other device.

More specifically, the device it) comprises a feeder bowl or material-retaining receptacle 14 formed so as to have a circular spiraling track originating at the bottom of the bowl and spiraling along the perimeter of the inner wall upwardly to an exit station. A bowl form of this sort is conventional and is adapted to receive a plurality of articles which may be progressively moved by vibratory energy from the lower portion of the bowl along the spiral track to the exit station at a given feed rate. Thereafter, as is well known to those skilled in the art of material-handling devices, the articles leaving the exit station can be transported through suitable means to other stations or directly for use for assembling purposes. The under-surface of the bowl 14 has a plate 16 rigidly secured thereto which in turn is connected by a plurality of inclined spring assemblies 18 to a base 26. As best seen in FIG. 2, four of these spring assemblies are provided for supporting the feeder bowl, and in this instance each spring assembly 18 has two leaf springs, it'being understood that this number can be increased or decreased depending on the size and capacity of bowl utilized.

At this juncture it should be noted that the materialhandling device described up to this point is conventional in construction and is adapted through the inclined spring assembly arrangement to provide a guided raising or lowering movement of the bowl to with simultaneous oscillation thereof whenever a vertically directed force is imposed on the central lower portion of the plate 16 in an upward or downward direction. Thus, Where force impulses of this sort are directed to the feeder bowl, the latter moves up and down at accelerations which permit the track to lose contact with the parts on the downstroke, and when contact is resumed on the up-stroke, the parts are located in advanced positions along the track.

The above-described device is driven through a lever arrangement generaliy indicated by the numeral 22 and which comprises an elongated bar or force-transmitting member 24 located between the bowl l4 and the base 20. The bar 24 has a pin 26 fixed to the upper portion thereof for engagement with a corresponding pin 28 secured to the underside of the plate to, and is supported at the lower portion thereof by the head of an adjustable bolt 3% and a coil spring 32. As can be seen clearly in FIG- URE l, the bolt 39 engages the bar 24. at a point offset from a vertical axis passing through the pins as and 28 while the coil spring makes contact with the bar. on the other side of the axis and provides a resilient support for the bar for reasons which will hereinafter be explained.

In order to prevent lateral shifting movement of the bar 24, a slotted block 34 is provided which accommodates a pin 36 rigidly fixed to the side of bar. 24 and projecting therefronn. A base plate 38 is fixed to the base 20 for supporting the bolt 3% and the block 3 and is located in an elevated position so as to permit adjustment of the bolt 30 in a vertical direction for raising or lowering one end of the bar 24 as will be more fully discussed hereinafter.

The lever arrangement 22 includes an air-operated vibrator 40 which has a movable piston housed therein for reciprocation and is driven by compressed air supplied to the vibrator through a conduit 42. The vibrator is mounted to the bar 24 through an intermediate con- .necting bar 44 and is so positioned that the reciprocating force impulses generated by the vibrator act on an axis perpendicular to the longitudinal axes of the bars 24 and It should be notedthat in the particular arrangement shown in FIG. 1, the bar 44 is used to connect the bar 24 of device to a corresponding bar 46 in device 12. Hence, the single vibrator serves to drive the lever arrangements of each feeder bowl associated with the respective devices. 'Of. course, where it is desired to drive one feeder bowl only, the connecting bar would not be necessary and the vibrator would be mounted directly to the lever.

As. should be apparent from the above, the lever rangement 22 constitutes a force-multiplying device in which the head of the bolt 30 serves as the fulcrum point,

30 and the vibrator is twenty times as great as the distance between the bolt 30 and the pin 26, the forces generated by the vibrator will be multiplied in value by twenty times or beequal to 300 pounds at the point of contact between the pins 26 and 28. This force can be increased or decreased by lengthening or shortening the distance between the vibrator and bolt 30 so as to increase or decrease the moment arm respectively. 7

An important feature provided by the present invention is a controlled preloading of the spring assemblies and coil spring 32 which among other. beneficial results causes the feeder bowl to move in phase with the force impulses generated bythe vibrator. This is accomplished through an adjustment provided by the bolt 30, the head of which contacts the underside of the bar 24. As mentioned above, this bolt is adjustable for raising or lowering that portion of the bar 24 disposed to one side of, the contact pin 26 by screwing the bolt into or out of base plate 38. Accordingly, prior to or while the vibrator is operating, the bolt 30 is rotated in a direction which permits it to extend upwardly with corresponding upward force being created against the underside of the :bowl through the contact pins 26 and 28. This adjustment iscontinued in an upward direction until the springassemblies and coil spring 32 are preloaded an amount sufficient to return the bowl in phase with the lever 24 when it is moved in a downward direction by the vibrator 49. Hence, irrespective of whet-her the lever '24- is driven by the vibrator upwardly or downwardly at the point defined by pin 26, the lever acts against a preloaded spring. I For example, when the force impulse generated by the vibrator is directed upwardly, this force is cushioned by the spring assemblies 318. On the other hand, the vibrators downward force impulse acts against the coil spring 32. It is believed that this preloaded spring arrangement in eifect provides controlled limits betweenwhich the lever and accordinglythe feeder bowl is raised and lowered. In addition, it is believed that the preloading of spring assemblies 18 permits the spirit of the invention.

feeder bowlto have a positive drive not only in an upward direction as supplied by an upward directed force impulse, but also while moving downwardly. This bidirectional drive may, at least partially, account for the constant feed rate of this device irrespective of the load .in the feeder bowl.

Another feature of the present invention is the ability 7 of utilizing a single vibrator, as shown in FIG. 1, for driving two or more feeder bowls. As seen in this figure and referred to above, the intermediate connection 44 joins the bar 24 with a bar 46 the latter of which is associated with a lever or force-multiplying arrangement similar to that employed in the device 10. By drilling a plurality of equally-spaced apertures 43 in the intermediate member 44, the vibrator can be positioned at varyingpoints along the intermediate member and also interconnect the two bars 24 and 46-. In this manner the moment arm v of each lever arrangement can be varied and, accordingly, the force delivered to the feeder bowl of each device can be adjusted.

In operating the present invention as depicted in FIG- URE 1, compressed air is supplied to the vibrator .40

through the conduit 42 resulting in a reciprocating vertical force impulse being delivered through the intermediate member 44 to the bars 24 and 46 of the devices 10 and 12, respectively, resulting in bar movement as shown in exaggerated form in FIGURE 4. The force generated by the vibrator is transferred through each of the bars to the associated bowl at amagnitude substantially greater than originally supplied by the vibrators. As the vibrator is operating, the preload on the springs is adjusted by upward movement of the adjustable bolt 30, as described above, with resulting high energy input being delivered to each of the feeder bowls. It has been found that a material-handling device operated by a leverarrangement incorporating the present invention can be loaded to capacity and after the preload adjustment of the springs is made the feed rate established at full bowl capacity will be maintained during the progressive dispensing of the parts up until the bowl is completely empty. Thus, this arrangement provides a material-handling device having a constant feed rate irrespective of the load in the bowl,

and thereby eliminates the frequent adjustment of the operating frequency of the vibrator or the requirement for the parts receptacle to have a substantially constant load therein. 7

Various changes and modifications can be made in the above-described device without departing from the V Suchchanges and modifications are contemplated by the inventor and, therefore, it should be understood that he does not desire to be limited except by the scope of the appended claims.

What is claimed is:

1. A vibratory material-handling device comprising a base, a feeder receptacle, a plurality ofinclined flexible members mounted on the base and connected to the feeder receptacle for supporting and guiding the latter for reciprocation in a confined inclined path of movement, a force-transmitting bar fulcrurned at a point on the base and having a portion thereof contacting the center ofthe feeder receptacle, meansincluding a spring for supporting the bar on the base for movement about the fulcrum point, and a vibrator mounted on the force-transmitting bar a distance from the receptacle center substantially greater than the distance between the fulcrum point and I the contact point of said bar portion so that the force impulses created by the vibrator are increased in mag nitude at said contact portion.

2. A vibratory material-handling device having a base, a feeder bowl, a plurality of inclined flexible members mounted on the base and connected to the feeder bowl for supporting and guiding the latter for reciprocation in a confinedinclined path of movement, a driving assembly for said feeder bowl located between the latter and the base, said assembly comprising a bar fulcrurnedon said i base and having a portion engaging the center of the under surface of the feeder bowl, means including a spring for supporting the bar on the base for movement in a vertical plane, a portion of said bar extending laterally outwardly from the feeder bowl center, a vibrator mounted on the bar so as to cause force impulses generated thereby to act in a direction transverse to the longitudinal axis of the lever, said vibrator being located a greater distance from the feeder bowl center than the bar fulcrum point so as to cause the force impulses generated by the vibrator to be increased in magnitude.

3. A vibratory material-handling device having a base, a feeder bowl, a plurality of inclined flexible members mounted on the base and connected to the feeder bowl for supporting and guiding the latter for reciprocation in a confined inclined path of movement, a driving assembly for said feeder bowl located between the latter and the base, said assembly comprising a bar fulcrumed on said base and having a portion engaging the center of the under surface of the feeder bowl, means including a spring for supporting the bar on the base for movement in a plane substantially normal to said under surface, a portion of said bar extending laterally outwardly from the feeder bowl center and having a plurality of equally-spaced apertures formed therein, a fluid driven vibrator mounted in one of said apertures so as to direct force impulses to said bar in a direction transverse to the longitudinal axis of the lever, said vibrator being located a greater distance from the feeder bowl center than the bar fulcrum point so as to cause the force impulses generated by the vibrator to be increased in magnitude.

, 4. The device of claim 3 wherein means are provided for preloading said flexible members and said spring.

5. A vibratory material-handling device comprising a base, a feeder receptacle, a plurality of flexible members mounted on the base and connected to the feeder receptacle for supporting and guiding the latter for movement in a confined path, a vibrator, means connecting the feeder receptacle with the vibrator in force-transmitting relationship and multiplying the force impulses of the vibrator so as to transmit to the feeder receptacle a force impulse having a greater magnitude than that created by the vibrator, support means for said means including spring means, and means for adjustably preloading said flexible members and said spring means whereby said receptacle has a substantially constant feed rate during operation of the vibrator.

6. An apparatus for driving two or more vibratory material-handling devices in which each of said devices has a feeder bowl resilient-1y supported by a base for guided movement in a confined path, said apparatus comprising force-multiplying means coupled with each feeder bowl in force-transmitting relationship, each of said forcemultiplying means comprising a bar fulcrumed at a point on the associated base and having a portion contacting said feeder bowl, means including a spring for supporting the bar on the base for movement, means interconnecting the bars of each feeder bowl, and a vibrator connected with said last-mentioned means to said bars for generating force impulses which are transmitted to each of the feeder bowls at an increased magnitude.

7. A vibratory material-handling device, comprising a base, a feeder receptacle, a plurality of flexible members mounted on the base and connected to the feeder receptacle for supporting and guiding the latter for movement in a confined path, a fulcrum mounted on said base, a bar having a first portion supported by said fulcrum and a second portion engaging the receptacle, a vibrator mounted on said bar at a third portion of the bar spaced from said fulcrum so that the force impulses generated by said vibrator are transmitted to the receptacle with increased magnitude, and spring means associated with said bar so that movement of the second portion in one direction is opposed by the flexible members and said spring means, said fulcrum being supported by said base for adjustable movement for preloading said spring means and flexible members.

References Cited in the file of this patent UNITED STATES PATENTS 2,671,655 Osterman Mar. 9, 1954 2,918,070 Carrier Dec. 22, 1959 FOREIGN PATENTS 26,606 Great Britain Dec. 30, 1901 808,337 Germany July 12, 1951 819,287 France Oct. 13, 1937 

1. A VIBRATORY MATERIAL-HANDLING DEVICE COMPRISING A BASE, A FEEDER RECEPTACLE, A PLURALITY OF INCLINED FLEXIBLE MEMBERS MOUNTED ON THE BASE AND CONNECTED TO THE FEEDER RECEPTACLE FOR SUPPORTING AND GUIDING THE LATTER FOR RECIPROCATION IN A CONFINED INCLINED PATH OF MOVEMENT, A FORCE-TRANSMITTING BAR FULCRUMED AT A POINT ON THE BASE AND HAVING A PORTION THEREOF CONTACTING THE CENTER OF THE FEEDER RECEPTACLE, MEANS INCLUDING A SPRING FOR SUPPORTING THE BAR ON THE BASE FOR MOVEMENT ABOUT THE FULCRUM POINT, AND A VIBRATOR MOUNTED ON THE FORCE-TRANSMITTING BAR A DISTANCE FROM THE RECEPTACLE CENTER SUBSTANTIALLY GREATER THAN THE DISTANCE BETWEEN THE FULCRUM POINT AND THE CONTACT POINT OF SAID BAR PORTION SO THAT THE FORCE IMPULSES CREATED BY THE VIBRATOR ARE INCREASED IN MAGNITUDE AT SAID CONTACT PORTION. 